Phosphorous-containing compounds and lubricants containing same

ABSTRACT

Phosphorus-containing compounds are provided that impart excellent extreme pressure properties to lubricants.

United States Patent [191 Olszewski Apr. 9, 1974 PHOSPHOROUS-CONTAINING {56] References Cited CONTAINING SAME 2,622,096 i2/l952 Ladd 252/499 X [75] Inventor: William F. Olszewski, Cherry Hill, 3,294,816 l2/l966 Latos et al. 252/499 X [73] Assignee: Mobil Oil Corporation, New York, Primary Emmmer w- Cannon NY Attorney, Agent, or Firm-Andrew L. Gaboriault; Raymond W. Barclay; Claude E. Setliff [22] Filed: Mar. 22, 1973 [21] App]. No.: 344,013 [57] ABSTRACT I Phosphorus-containing compounds are provided that [52] U.S. Cl. 252/499, 260/326 E impart excellent extreme pressure properties to lubri- [51] Int. Cl C10m 1/46 m Field of Search 252/499; 260/326 E 8 Claims, No Drawings PI-IOSPI-IOROUS-CONTAINING COMPOUNDS AND LUBRICANTS CONTAINING SAME BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a new class of phosphoruscontaining compounds and to the use as lubricant additives. More particularly, it relates to compounds made by reacting certain anhydrides with phosphoramidates as lubricant additives.

2. Discussion of the Prior Art It is known that sliding or rubbing metal or other solid surfaces are subject to wear under conditions of extreme pressure. Wearing is particularly acute in modern engines in which high temperatures and contact pressures are prevalent. Under such conditions, severe erosion of metal surfaces can take place, even with lubricants of ever-increasing sophistication, unless a load carrying additive is present. As a consequence, much effort has been expended to discover additives useful in preventing such wear.

With certain metals, and under certainconditions, especially high temperature conditions, many of the conventional additives, although they may impart extreme pressure properties, may cause or permit corrosion of the metal. The compounds of this invention are not corrosive to metals such as'copper.

SUMMARY OF THE INVENTION In accordance with the invention, there are provided compounds of the formula atoms and such R may be the same or different, X is halogen (e.g. chlorine, bromine, fluorine and iodine), Y is halogen, hydrogen or alkyl offrom l to 10 carbon atoms, m is l to 4, n is to 4 and p is 0 to 4. The invention also provides lubricant compositions comprising a lubricant and an extreme pressure amount of the compounds described.

As used herein, hydrocarbyl" shall be understood to mean alkyl of 1 to 22 carbon atoms, cycloalkyl of 3 to 10 carbon atoms, aralkyl, aryl and allraryl of 6 to 40 carbon atoms. It will be further understood that the R groups can be the same or different hydrocarbyls.

DESCRIPTION OF SPECIFIC EMBODIMENTS In general the compounds are made byemploying reactions well known in the art. That is they are formed by reacting an anhydride-containing compound with an amino-containing compound under conditions such that an imido structure is formed. Thus a polyhalopolyhydropolycyclidi carboxylic anhydride and a phosphoramidate will react in the following manner to yield the indicated product.

pll X 0 and CA 70, 288 (1969).

The reaction is preferably carried out in a non-polar solvent having a boiling point in the range of from about C to about 200 C. The more preferred solvents are aromatic hydrocarbons boiling in the range of about -l20 C. The boiling range is not critical, however, and any suitably non-polar solvent can be used so long as it has a boiling point high enough to permit adequate temperatures of reaction and so long as it can be easily separated from the product.

Under properconditions, the reaction will normally take from 4 to 14 hours, but conditions are preferably chosen so theproduct can be obtained in maximum yield in from 6-8 hours.

The additives of this invention can be used in a wide variety of lubricant media. Thus they are effective agents for lubricating oils such as mineral oils, both naphthenic and paraffinic, including those containing substantial amounts of aromatic oils. They are also effective for synthetic oils, such as synthetic hydrocarbons, which are obtained by polymerizing olefins, synthetic esters and for polysiloxanes and the like. The term lubricant also includes greases made from any of the mentioned lubricating oils by adding a grease forming agent thereto. One particular ester oil of importance is one made by reacting an aliphatic monocarboxylic acid containing from 4 to 10 carbon atoms, preferably 5 to 9, with pentaerythritol. A widely used lubricating oil is made from monopentaerythritol and a mixed C and C acid.

When used for the purposes herein disclosed, the additives are effective at from about 0.02% by weight to about 10.0% by weight, preferably from about 0.10% to about 2.0%.

The following examples will serve to illustrate the invention. It should be kept in mind that they are for illustration only and are not intended to limit the inventive scope. Parts are by weight unless otherwise indicated.

EXAMPLE 1 PART A Preparation of di-n-butyl phosphoramidate. Ammonia (37 g., 2.2 moles) was bubbled into a solution of di-n-butyl phosphonate (194 g., 1.0 mole) and carbon tetrachloride (154 g., 1.0 mole) in xylene (500 chloride by filtration the solvents were removed by topping to a pot temperature of 100 C at mm pressure.

Fractional distillation. of the residue yielded di-n-butyl phosphoramidate (bp l33-l39 C, 0.1 mm).

Product Analysis: Phosphorus 15.7 Nitrogen 6.4

PART B EXAMPLE 2 PART A Preparation of dioleyl phosphoramidate. In a manner similar to Example l, Part A, dioleyl phosphoramidate was'prepared from dioleyl phosphonate (279 g., 0.5 mole), carbon tetrachloride (154 g.,

0.5 mole), xylene (500 ml) and ammonia (17 g., 1.0 mole).

Product Analysis: Phosphorus 5.9

% Nitrogen 2.2

PART B Preparation of 2-dioleoxyphosphinyl 4,5,6,7,8,8- hexachloro-3a,4,7,7atetrahydro-4,7- I methanonaphthalimide.

In a manner similar to Example 1, Part B, l,4,5 ,6,7,7- hexaChloro-S-norbornene-2,3-dicarboxylic anhydride (74 g., 0.2 .mole) was reacted with dioleyl phosphoramidate 115 g., 0.2 mole) in toluene 200 ml) t give the product. Product Analysis:

% Phosphorus 3.7

PRODUCT EVALUATION LOAD- CARRYING TEST The load-carrying capacity of a lubricant is measured under high speed shock conditions. The oilsampleis placed in an SAE 1000 test rnachine as a lubricant for two steel test rings which are rotated against each other at different speeds, the faster at 1,000 rpm. Such rotation produces a combination of rolling and sliding actions. As rotation proceeds, the load holding the rings together is gradually increased by mechanical means until either the maximum load of the machine load is reached or until the rings seize, or fail to rotate. The

' maximum measurable loading for the machine used'in this test is 460 lbs. The results are reported in pounds at seizure.

Table 1 shows the improved load-carrying properties of the additives of the invention.

MODIFIED SAE TEST Table 2 summarizes the results of a test described below.

The sample size used was 600 cc per run. The SAE extreme pressure lubricant testing machine was used in which two contra-rotating steel test rings (cups) turn at different speeds and roll and slide in line contact under controlled pressure. By the use of pulleys, the main shaft (upper) rotates at 156 rpm while the secondary (lower) shaft rotates at a lower speed that gives a slip ratio of 14.621.

Line contact pressure (load) is applied automatically at a constant rate of 7-8 lb (on the scale) per second. An oil recirculation system pumps the oil from the heated oil reservoir through a heated oil line to the cradle containing the cups. The oil overflows from a port in the cradle and returns by gravity to the oil reservoir. Two thermocouples, one in the reservoir and one in the oil delivery tube in the area of the test cups, help in controlling the temperature of the lubricant. The two thermocouples are connected with a temperature control system that regulates the heating. If desired, a simple temperature recorder can be connected to obtain a permanent record of the oil temperature through the test. k

The test cups are cleaned, dried, weighed to the nearest milligram, and mounted on the two shafts. Check must be made of the alignment of the cups for proper contact and a runout of no more than 0.0005 in. Then the test oil, 600 cc, is poured in the oil reservoir and heated with recirculation to 275 F. When the temperature of the oil in the delivery tube is stabilized at 275 F, :2 F, the break-in load of 20 lb scale (400 in.-lb) is applied and the machine is started. The break-in lasts exactly sec. After that, the load is gradually increased to 400 lb scale and stabilized there for 45 minutes.

If seizure occurs during break-in or during the load application, the machine is stopped and the oil is rated fail-seizure. If the run is completed for the full 45 minutes, the cups are removed, cleaned, weighed to the nearest milligram, and examined for surface distress. If a seizure occurred, no weighing or further examination is necessary. I

Table 3 shows the improved load carrying properties in the Shell F our-Ball Machine of a mineral oil containing additive amounts of the novel compounds described herein.

Table 4 shows the improved load-carrying properties in the Shell Four-Ball Machine of a synthetic oil containing additive amounts of the novel compounds described herein.

Table 5 illustrates the stability of these compounds in the Copper Corrosion Test, ASTM -Method Dl306 (250 F, 3 hours).

IABLEI R x Y P M N 1000 SAE Load Carrying Test Methylc1 c1 1 1 1 Octyl c1 1 Additive Conc.. P Seizure Load r yl Cl 0 l Eicosyl C1 Cl 1 1 1 Base Oil None 50 Phenyl C1 C1 1 l 1 Example 1 0.15 310 y p y Cl 0 l Part 5 Example 2 0.15 400 Part B Base 01 used was an Ali 90. sohent refined Mrd-conlrnent oil. 1. A lubricating composition compr sing a major amount of lubricating oil or grease and a wear or extreme pressure improving amount of a compound of W TABLE 2 the formula 156 SAE Wear Test 5 Additive Cone. P Wear (mg.) X E Base 011 None Fail at 160 lbs. /I\ o 0 Example l 0.15 32 Example 2 0.15 10 x;

Part B OR X k J1 11 Base oil used was an SAE 90. solvent refined Mid-continent oil. aka mV 7 TABLE 3 Scar Diameter (mm), 60 Kg, minutes Cone. 80F 390F Additive P 500 RPM 1000 RPM 1500 RPM 500 RPM 1000 RPM 1500 RPM Base Oil None 0.60 0.71 1.00 0.85 1.66 2.00

Example 1 0.04 0.46 0.56 0.65 0.60 0.55 1.30

Part B Base 011 used was an SAE 90, solvent refined Mid-continent oil.

ABL 4 Scar Diameter (mm), Kg, 30 Minutes Conc., 80F 390F r Additive P 500 RPM 1000 RPM 1500 RPM 2000 RPM 500 RPM 1000 RPM 1500 RPM Base Oil None 0.72 0.93 1.13 2.00 0.91 2.24 2.24

Example 1 0.04 0.49 0.69 0.78 0.75 0.61 0.60 1.90

Base oil used was apentaerythritol ester of mixed C -C acids Base oil used was an SAE 90, solvent refined Mid-continent oil.

The following are additional compounds contemplated by the invention.

wherein R is a hydrocarbyl of from 1 to 40 carbon atoms, X is halogen,'Y is halogen, hydrogen or alkyl of from 1 to 10 carbon atoms, m is 1 to 4, n is 0 to 4 and p is 0 to 4.

2. The composition of claim 1 wherein the compound is present at a concentration of from about 0.02% to about 10.0% by weight.

3. The composition of claim l wherein the lubricant is a lubricating oil.

4. The composition of claim 1 wherein the lubricant is a grease.

5. The composition of claim 3 wherein the lubricating oil is .a mineral lubricating oil.

8. The composition of claim 1 wherein the compound is one in which R is oieyl, X is chloro, p is zero and n is l. 

2. The composition of claim 1 wherein the compound is present at a concentration of from about 0.02% to about 10.0% by weight.
 3. The composition of claim 1 wherein the lubricant is a lubricating oil.
 4. The composition of claim 1 wherein the lubricant is a grease.
 5. The composition of claim 3 wherein the lubricating oil is a mineral lubricating oil.
 6. The composition of claim 3 wherein the lubricating oil is a synthetic ester lubricating oil.
 7. The composition of claim 1 wherein the compound is one in which R is butyl, X is chloro, p is zero and n is
 1. 8. The composition of claim 1 wherein the compound is one in which R is oleyl, X is chloro, p is zero and n is
 1. 